BT, Nokia crack four carrier aggregation on a 5G network in first for Europe

BT and Nokia have announced the successful combination of four carrier components (4CC) in a 5G standalone network (SA), marking a major step towards greater 5G connectivity on its EE network and a first for Europe.

In a blog post, the telecommunications giant celebrated the successful test and the potential it carries for future networking. Carrier aggregation, in which multiple carrier bands are merged to form a stable connection, can provide dramatically improved bandwidth and speeds not capable on any of the carriers on their own.

The majority of 5G networks across the UK use existing 4G infrastructure, making them ‘non-standalone’. Successful implementation of BT’s new 5G SA would grant businesses and consumers widespread network speed improvement and open a new door for creative use of authorised bandwidths.

In another European first, the trial was successfully performed not only in lab conditions but also from a radio mast at BT’s Adastral park in Suffolk. Proof of a working 5G standalone network utilising 4CC is a major step forward for UK 5G, particularly as the team was able to run the 5G network on EE’s existing radio spectrum.

Pre-5G network standards such as LTE-A use carrier aggregation to combine up to five networks together to reach a total speed equivalent to ‘true 4G’. In the case of the announced tests, low and mid-band radio channels in the frequencies 2.1, 2.6, 3.4 and 3.6 GHz were combined using Nokia’s 5G radio access network and a MediaTek M80 5G modem.

“Our trial with Nokia is another demonstration of building the most advanced network for our customers,” stated Greg McCall, managing director of service platforms at BT.

“5G Standalone, coupled with edge compute, will unlock new opportunities for customers looking to develop new services. Furthermore, this technology showcases what’s possible for devices in the future in terms of supporting carrier aggregation, which is an important part of customer experience.”

The rollout of the UK 5G network has seen several setbacks, most notably the government’s 2020 order for BT to remove all Huawei equipment from its core network by January 2023. BT has since stated that it may not be able to meet this target and has asked for an extension citing the impact of covid on the removal process.

There is also growing industry interest in the use of millimetre wave (mmWave), generally defined as the bands between 24-100GHz. BT EE has indicated that they are seeking whole market approval for mmWave, which offers high speeds and little interference, and is currently seeing success utilising the lower end of this spectrum for fixed wireless access such as in stadiums and conference centres.

However, Ofcom has yet to auction off the mmWave spectrum, and BT will face stiff competition from satellite operators when the time comes, with many questions remaining around the best use cases for the 40GHz band. Even as 5G is yet to be properly capitalised upon, the government is working towards 6G through programs such as its recently announced collaborative research scheme with South Korea.

Despite setbacks, BT has several plans in place to dramatically expand its 5G network as well as to boost network technology development. In May, it announced a partnership with Swedish multinational Ericsson to develop private 5G networks for commercial clients.

BT also signed a memorandum of understanding last year with UK satellite communications company OneWeb, in the interest of improving broadband reach for rural customers such as small to medium businesses (SMBs). OneWeb seeks to provide global broadband internet services by the end of 2023 through the use of its low earth orbit satellite constellation, and last month entered into merger talks with French satellite operator Eutelsat.